Question

When I click on a PDF, a new tab opens. It gives me the option to open the document directly or save it--this is what I have preferences set to do. However, when I try either of those options nothing happens. It only opens a new blank tab. My specifications are below. I've run all the relevant software updates.

System: OS X 10.8.2

Adobe Reader: 10.1.5

Firefox: 18.0.1

I've seen this problem on other posts and I've done some searching on the web. I've tried the solutions that have been provided and worked for other people, however I noted that they were running older versions of some of the software, etc. Interestingly, I CAN open PDFs that come to me or that I send through Gmail.

I have done the following based on the advice I've seen:

Cleared my downloads list

Tried disabling the Adobe NPAPI Plug-In

In my Firefox preferences: I have set PDF documents to be open by Adobe. I also tried it with Preview. Neither of them worked.

The mimeTypes.rdf file does not contain any bookmarks or personal data. If you are concerned about potential data loss, please make a backup of the contents of your personal settings (Firefox profile) folder before making any deletions.

In Preferences--Applications it seems as though the default for some items is "always ask" which doesn't happen! I changed "Preview Document (application/pdf)" from "always ask" to "Use Adobe Reader". I also changed "Preview Document (x-unknown/pdf)" from "always ask" to "Save File". Now the desired content opens in a new window & is downloaded to my desktop (my preference). I use a Mac & am not a computer whiz. This seems like a really stupid problem related to the newest version of Firefox.

I have the same PDF problem which also has recently appeared. I am using Windows 7 on a 64 bit PC. I have tried multiple options/applications action settings for PDF and none appear to take effect. IE and Chrome work fine.

This what worked very well for me.
In case your application preferences file has become corrupted, you could try renaming or deleting it.
Help > Troubleshooting Information > "Show Folder"
The file is named mimeTypes.rdf and if you rename or delete it, it should be regenerated with default the next time you restart Firefox.

That did it! Well some combination of what you said and all the updating stuff. I did try the PDF extension that Huvotnl suggested b/f doing what you suggested, but it didn't work. Anyway, that's months of frustration every time I wanted to download something now resolved.

Now, can you help me understand WHY that worked? How does renaming something change what's inside the file? Also, how did the file get corrupt? Is that any indication of a virus or some other larger problem I should be worried about? Not a tech guy here.

Also, I'm presuming that none of my other info, most importantly bookmarks, were lost, etc. I checked and they all seem to be there in the list. I just like to understand stuff.

Hi kylevmorris, the mimeTypes.rdf starts out with a limited set of pre-defined application handlers. This can be modified by plugins, data from the Windows registry, changes you make in Application options (Options>Applications or Preferences>Application), and choices you make in the Open/Save/Cancel dialog.

Because there's no supervisor in Firefox making sure the file is completely coherent, it sometimes becomes, for lack of a better phrase, messed up. When you rename or delete the file (the file in your active personal settings folder accessible using Help > Troubleshooting Information > Show Folder button), you restart the process of building the list of application handlers. Everything should be good unless/until it becomes messed up again.

(Note that the mimeTypes.rdf is a text file that you could try editing by hand, but due to its poorly documented structure, and Firefox's ability to rebuild it, it's usually easier to just rename or delete it when there are problems.)

On Windows, click the orange Firefox button or click the Tools menu, then choose Options.

On Mac, click the Firefox menu then Preferences.

On Linux, click the Edit menu then Preferences.

(2) Click Applications and pause while the list is displayed. Type pdf in the search box to filter the list.

(3) Click the drop-down control to the right of "Portable Document Format (PDF)" to change it from "Preview in Firefox" to your preferred handler for PDFs. For example, if you prefer to open PDFs in a Firefox tab using Adobe's plugin, choose "Use Adobe Acrobat (in Firefox)".

(4) Click OK to save your change and close the Options/Preferences dialog.

Hi mjkessler5, that sounds like an ordeal. Next time (hopefully there won't be a next time), instead of doing an uninstall/reinstall and removing all settings, try using the Reset feature first: Refresh Firefox - reset add-ons and settings. This preserves many settings that usually aren't implicated in functional problems (for example, bookmarks) while giving you a fresh start on other settings.